Reviewed by King (1954) and Repenning et al. (1971) who included Arctophoca Peters, 1866. Van Gelder (1977b) considered Zalophus and Arctocephalus congeneric. Nearly all species of Arctocephalus are distributed allopatrically (Rice, 1998). Synonyms allocated according to Gardner and Robbins (1998). Allen (1905) discussed confusion in designation of type species.